气相色谱手性衍生化试剂N－七氟丁酰基－L－脯氨酰氯的合成与应用

合成了用于气相色谱（ＧＣ）的手性衍生化试剂Ｎ－七氟丁酰基－Ｌ－脯氨酰氯（Ｎ－ＨＦＢ－Ｌ－ＰＣｌ）。各种特性试验表明，Ｎ－ＨＦＢ－Ｌ－ＰＣｌ是灵敏的ＧＣ手性衍生化试剂，可直接于水相拆分微量的手性胺对映体。     

气相色谱手性衍生化试剂N－七氟丁酰基－L－脯氨酰氯的合成与应用

 合成了用于气相色谱（ＧＣ）的手性衍生化试剂Ｎ－七氟丁酰基－Ｌ－脯氨酰氯（Ｎ－ＨＦＢ－Ｌ－ＰＣｌ）。各种特性试验表明，Ｎ－ＨＦＢ－Ｌ－ＰＣｌ是灵敏的ＧＣ手性衍生化试剂，可直接于水相拆分微量的手性胺对映体。     

全烷基化和部分烷基化三氟乙酰化的α-环糊精手性毛细管色谱柱分离对映体

合成了全戊基化和部分戊基化三氟乙酰化的两种α-环糊精手性固定相.制备出柱效在3500塔片/m以上的高效手性毛细管柱,分离了一些对映体及不对称合成中的中间体,如α-苯乙胺,α-苯丙胺、酒石酸酯和缩酮等.结果表明,三氟乙酰化的α-环糊精衍生和的对手性醇、胺和酯等对映体的选择性比全戊基化的环糊精高.对映体中引入的衍生化基团对选择性也有明显影响.     

配体交换毛细管区带电泳拆分未衍生化氨基酸

以铜（Ⅱ）-L-谷氨酸络合物为手性分离选择剂，对苯丙氨酸、酪氨酸和色氨酸3种非衍生芳香族氨基酸的手性对映体拆分进行了研究，建立了一种快速、简便拆分未衍生化的氨基酸对映体的配体交换毛细管电泳方法。在使用10mmol／L NH4AC（pH5．0），5mmol／L CuSO4和10mmol／L L-谷氨酸的条件下，成功地拆分了苯丙氨酸、酪氨酸手性对映体；色氨酸手性对映体也得到部分分离；考察了电泳缓冲液组成、pH值等影响分离效果的因素。     

三七素手性拆分方法的研究

使用气相色谱法和高效液相色谱法分离了三七素对映体,并探讨了影响液相色谱法分离效果的因素。结果表明,HPLC法利用手性固定相进行直接拆分,无法实现对映体的完全分离;GC法和HPLC的手性试剂衍生化法均可对三七素对映体进行较好的分离。但GC法由于衍生化过程中副产物的存在,干扰了对映体的准确定量。手性试剂衍生化HPLC法,以邻苯二甲醛、N-酰化-L-半胱氨酸为衍生化试剂,反应得到的三七素对映体的衍生物在ODS柱上分离良好,且方法简单、快速。     

卡替诺尔和氟西汀对映体的高效毛细管电泳分离

考察了以羧甲基－β－（环糊精－β－CD）、β－环糊清（β－CD）、羟丙基－β－环糊精（HP－β－CD）、二甲基－β－环糊精（DM－β－CD)为手性选择剂,在50mmol/L醋酸三乙胺缓冲溶液中分离卡替诺尔和氟西汀对映体。该文还通过考察手性选择剂的浓度、背景电解质的酸度、背景电解质的类型等因素对映体手性分离的影响,对分离条件进行了优化,初步探讨了手性识别机理。实验结果表明：用约4mmol/L的CM－β－CD分离氟西汀和卡替诺尔对映体,能使对映体达到良好分离,不仅节约了分析成本,也简化了分析过程。     

牙本质中天冬氨酸消旋化程度的测定——手性毛细管气相色谱法与高效液相色谱法的比较

 应用手性毛细管气相色谱法（酸性异丙醇、三氟乙酸酐为衍生试剂）、高效液相色谱法（邻苯二甲醛－Ｎ－乙酰－Ｌ－半胱氨酸为手性衍生试剂）同时测定人类第一磨牙牙本质中天冬氨酸的消旋化程度，结果表明，两者均可有效地用于天冬氨酸对映体的分离测定，但气相色谱检测限（０．２ｐｍｏｌ）低于高效液相色谱（１．０ｐｍｏｌ），而变异系数（７％）、总分析时间（１００ｍｉｎ）均高于高效液相色谱（分别对应为４％，３１ｍｉｎ）。     

牙本质中天冬氨酸消旋化程度的测定——手性毛细管气相色谱法与高效液相色谱法的比较

应用手性毛细管气相色谱法（酸性异丙醇、三氟乙酸酐为衍生试剂）、高效液相色谱法（邻苯二甲醛－Ｎ－乙酰－Ｌ－半胱氨酸为手性衍生试剂）同时测定人类第一磨牙牙本质中天冬氨酸的消旋化程度，结果表明，两者均可有效地用于天冬氨酸对映体的分离测定，但气相色谱检测限（０．２ｐｍｏｌ）低于高效液相色谱（１．０ｐｍｏｌ），而变异系数（７％）、总分析时间（１００ｍｉｎ）均高于高效液相色谱（分别对应为４％，３１ｍｉｎ）。     

手性试剂TMPEA用于手性酮对映体纯度测定的研究

β-三氟甲基-β甲氧基β-苯基乙胺（TMPEA）是含氨基功能团的手性试剂[1]．由于胺可将按酸转变成酸胺，该试剂已成功地用于手性有机酸对映体的纯度测定[2]．考虑到胺同样可将醛酮转变成亚胺，本文进一步探讨了TMPEA用于手性醒酮对映体纯度测定的可行性．用R－（－）－TMPEA及dl－TMPAE分别与下列4种手性酮反应，制备相应的非对映异构亚胶：比较光活亚胺及相应的非对映异构体混合物亚腔的NMR谱，可确定各组非对映异构亚胺‘HNMR位移差（以OCH为探针基团）和’‘FNMR的位移差（以CF为探针基团）（表1）．TablelCheffiicalshif…     

七(2,6-二-O-戊基-3-O-三氟乙酰基)-β-环糊精用于对映体分离

用七（２，６－二－Ｏ－戊基－３－Ｏ－三氟乙酰基）－β－环糊精分离了胺类、氨基酸类、环氧化物和卤代烃等对映体，测定了α、－Δ（ΔＨ）、－Δ（ΔＳ）及Δ（ΔＨ）／Δ（ΔＳ）值，通过和文献数据比较，观察到同系物的Δ（ΔＨ）／Δ（ΔＳ）值接近于一个常数，且和所用手性固定相及是否发生“包结”作用无关。     

Stereoselective screening for and confirmation of urinary enantiomers of amphetamine, methamphetamine, designer drugs, methadone and selected metabolites by capillary electrophoresis.

Data presented in this paper demonstrate that a competitive binding, electrokinetic capillary-based immunoassay previously used for screening of urinary amphetamine and analogs cannot be employed to distinguish between the enantiomers of amphetamine and methamphetamine. However, capillary zone electrophoresis with a pH 2.5 buffer containing (2-hydroxypropyl)-beta-cyclodextrin as chiral selector is shown to permit the enantioselective analysis of urinary extracts containing methamphetamine, amphetamine, 3,4-methylenedioxymethamphetamine (Ecstasy) and other designer drugs, and methadone together with its major metabolite, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine. In that approach, enantiomer identification is based upon comparison of extracted polychrome UV absorption data and electropherograms obtained by rerunning of spiked extracts with spectra and electropherograms monitored after extraction of fortified blank urine. The suitability of the described chiral electrokinetic capillary method for drug screening and confirmation is demonstrated via analysis of unhydrolyzed quality control urines containing a variety of drugs of abuse. Furthermore, in a urine of a patient under selegiline pharmacotherapy, the presence of the R-(-)-enantiomers of methamphetamine and amphetamine could be unambiguously identified. Direct intake of an R-enantiomer or ingestion of drugs that metabolize to the R-enantiomers can be distinguished from the intake of S-(+)-enantiomers (drug abuse) or prescribed drugs that metabolize to the S-enantiomers of methamphetamine and amphetamine. The described approach is simple, reproducible, inexpensive and reliable (free of interferences of other major basic drugs that are frequently found in toxicological urines) and could thus be used for screening for and confirmation of urinary enantiomers in a routine laboratory.     

Liquid chromatographic method for the determination of enantiomeric composition of amphetamine and methamphetamine in hair samples

Interest in hair analysis as an alternative or complementary approach to urinalysis for drug abuse detection has grown in recent years. Hair analysis can be particularly advantageous for drugs such as amphetamine and methamphetamine that are rapidly excreted. Confirmation of abuse of these stimulants is complicated by the fact that some forms are found in legitimate medications. Examination of the enantiomeric composition of amphetamine and methamphetamine in hair samples can provide valuable assistance in interpreting drug testing results. In this work, we developed a liquid chromatographic method for the separation of amphetamine and methamphetamine enantiomers isolated from human hair samples. The drug enantiomers were separated on a chiral stationary phase after derivatization with an achiral fluorescent agent. The methodology was evaluated with a Standard Reference Material that contained several drugs of abuse including amphetamine and methamphetamine.Contribution of the National Institute of Standards and Technology. Not subject to copyright.     

Simultaneous chiral analysis of methamphetamine and related compounds by capillary electrophoresis/mass spectrometry using anionic cyclodextrin.

A capillary electrophoresis/mass spectrometry method for the simultaneous chiral analysis of enantiomers of methamphetamine (MA), amphetamine (AP), dimethylamphetamine (DMA), ephedrine (EP), norephedrine (NE) and methylephedrine (ME) in urine has been developed. The background electrolyte was 1 M formic acid (pH 1.7). Using 0.85 mM heptakis(2,6-diacethyl-6-sulfato)-beta-cyclodextrin as the chiral selector, the 12 enantiomers were completely separated within 25 min. The detection limits were 0.01 microg mL(-1) for the enantiomers of MA, AP, DMA, EP and ME, and 0.02 microg mL(-1) for the enantiomers of NE using selected ion monitoring. The reproducibilities of within-run (n = 4) for the migration times and peak areas of the standard mixture were under 0.58% and 7.83%, respectively. The calibration curves of the peak areas of the 12 enantiomers were linear in the range of 0.05 - 10 microg mL(-1). This method was applicable to the analysis of urine samples.     

Separation of the enantiomers of primary and secondary amphetamines by liquid chromatography after derivatization with (−)-1-(9-fluorenyl)ethyl chloroformate

Summary The chiral reagent (−)-1-(9-fluorenyl)ethyl chloroformate (FLEC) has been evaluated for the enantioselective analysis of amphetamines by liquid chromatography. For separation of the FLEC diastereomers conventional reversed-phase conditions were used. The conditions affording the best enantiomeric resolution and sensitivity were determined for amphetamine, methamphetamine, ephedrine, pseudoephedrine, 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxymethamphetamine (MDMA), and 3,4-methylenedioxyethylamphetamine (MDE). All the amphetamines assayed could be separated with resolution factors ranging from 0.91 to 1.92. Although FLEC is typically used as a fluorogenic reagent, it was shown that UV detection is the best option for stereospecific analysis of the methylenedioxylated amphetamine derivatives (MDA, MDMA, and MDE), because different fluorimetric responses were obtained for the corresponding diastereomers. The utility of the proposed conditions for stereoselective analysis of amphetamines in different types of sample is discussed.     

苯丙胺类、氯胺酮、卡西酮类毒品手性分离的研究进展

对映异构体在自然界中普遍存在,在药物化学领域尤为突出。虽然手性药物的对映异构体之间具有相同的化学结构,但它们在药理、毒理、药代动力学、代谢等生物活性方面存在明显差异。苯丙胺类、氯胺酮、卡西酮类毒品也是如此,这3类毒品的手性分离研究在常见毒品中具有代表性。目前常用的手性分离色谱方法有气相色谱法(GC)、高效液相色谱法(HPLC)和毛细管电泳法(CE)。苯丙胺类、氯胺酮、卡西酮类毒品使用以上3种方法进行的手性分离研究具有一定共性:GC较多使用N-三氟乙酰-L-脯胺酰氯和(+)R-α-甲氧基α-三氟甲基苯乙酸两种典型的手性衍生化试剂,HPLC主要应用蛋白质类、多聚糖类和大环抗生素类3种手性固定相,CE中环糊精及其衍生物是最常用的手性选择剂。然而这3种手性分离方法存在各自的不足,GC存在手性衍生化引入杂质、反应温度高影响手性分离等问题,HPLC的应用范围比较有限,成本较高,CE没有明确的方法判断哪种物质是合适的手性选择剂。近年来,这3类毒品的手性分离研究在法医毒物学领域的应用有各自的特点,苯丙胺类毒品的手性分离研究多用于推断市场上毒品的原型及合成路线,氯胺酮的手性分离研究涉及多种生物检材,卡西酮类毒品侧重于手性分离方法的广泛适用性。该文主要遴选近10年国内外核心期刊的文献,对苯丙胺类、氯胺酮、卡西酮类毒品的手性异构体特点及色谱法的手性识别机理进行简单介绍,重点对已有研究的共性以及手性分离在法医毒物学中的应用等内容进行综述。基于以上研究,该文提出未来可以从以下3个方面进行深入研究:一是利用计算机技术建立分子模型深入探究手性识别机理;二是研发新型技术,对超临界流体法进行商用研究;三是将手性分离应用于司法实践、医药研发等实际工作领域。     

毛细管区带电泳法拆分手性药物萘普生和氟联苯丙酸

 70-72 -------------------------------------------------------------------------------- 以β-环糊精(CD)作为手性选择剂 ,用毛细管区带电泳法成功地拆分了两种弱酸性药物萘普生(naproxen)和氟联苯丙酸(flurb iprofen),并比较了4种环糊精［β-环糊精(β-CD)、二甲基-β-环糊精( DM-β-CD)、羟丙基-β-环糊精(HP-β-CD)和三甲基-β-环糊精( TM-β-CD)］对手性拆分的影响,同时测定了萘普生对映体在不同环糊精中的出峰次 序。通过实验,发现对于此类化合物拆分的最佳pH值为5左右,即接近于该类化合物的pK a值。该方法适用于酸性手性药物的拆分。     

Simultaneous enantiomeric determination of MDMA and its phase I and phase II metabolites in urine by liquid chromatography–tandem mass spectrometry with chiral derivatization

A liquid chromatography–electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) procedure was developed for the simultaneous determination of enantiomers of the prevalent designer drug 3,4-methylenedioxymethamphetamine (MDMA) and its phase I and phase II metabolites in urine with chiral derivatization. The analytes in urine were directly derivatized with chiral Marfey’s reagent, N ^α- (5-fluoro-2,4-dinitrophenyl)-d-leucinamide, without extraction. The diastereomers of the N ^α-(2,4-dinitrophenyl)-d-leucinamide derivatives generated were determined by LC-MS/MS. Satisfactory chromatographic separation was achieved for the enantiomers of MDMA and its metabolites 3,4-methylenedioxyamphetamine, 4-hydroxy-3-methoxymethamphetamine (HMMA), HMMA glucuronide, and HMMA sulfate on a semimicro octadecylsilane column using linear gradient elution. With use of multiple reaction monitoring mode, the limits of detection of these analytes ranged from 0.01 to 0.03?μg/mL. Linear calibration curves were obtained for all enantiomers from 0.1 to 20?μg/mL in urine. The method showed sufficient reproducibility and quantitative ability. This is the first report of a simple LC-MS/MS-based analytical procedure with direct chiral derivatization in aqueous media that allows simultaneous enantiomeric determination of drugs and their metabolites, including glucuronide and sulfate derivatives.     

Cyclodextrins as chiral stationary phases in capillary gas chromatography. Part III: Hexakis(3-O-acetyl-2,6-di-O-pentyl)-α-cyclodextrin

The properties of hexakis(3-O-acetyl-2,6-di-O-pentyl)-α-cyclodextrin as a chiral stationary phase for capillary gas chromatography are described. For the first time the enantiomers of a series of different lactones are separated and their order of elution is assigned. Moreover, the enantiomers of trifluoroacetylated aldols and amino alcohols, the cyclic carbonates of 1,2-diols, 1,3-diols, O-alkylated glycerols, and some chiral pharmaceuticals are also separated on the new chiral phase. The modified α-cyclodextrin is stable above 200°C.     

Simultaneous chiral determination of methamphetamine and its metabolites in urine by capillary electrophoresis-mass spectrometry

A capillary electrophoresis-mass spectrometry method for the simultaneous chiral determination of enantiomers of methamphetamine (MA), amphetamine (AP), dimethylamphetamine (DMA) and p-hydroxymethamphetamine (pOHMA), in urine has been developed. The internal standards used were 2-phenylethylamine and 1-amino4-phenylbutane. The electrolyte was 1 M formic acid (pH 2.2). The chiral selector, which was added to the electrolyte, was a mixture of 3 mM beta-cyclodextrin and 10 mM heptakis(2,6-di-O-methyl)-beta-cyclodextrin. The detection limits were 0.03 microg ml(-1) for the enantiomers of MA and AP and 0.05 microg ml(-1) for the enantiomers of pOHMA using selected ion monitoring. In the analysis of healthy adult urine samples spiked with MA, AP and pOHMA, the precision of within-run assays (n = 4) for the migration time after correction with two internal standards were under 0.04%, and the detection yields utilizing solid phase extraction were 95-105%. This method was applicable to the analysis of urine samples of MA addicts and DMA addicts.     

Quantification of methamphetamine, amphetamine and enantiomers by semi-micro column HPLC with fluorescence detection; applications on abusers' single hair analyses

Achiral and chiral semi-micro column high-performance liquid chromatographic methods with fluorescence detection to determine methamphetamine and amphetamine in human hair are described. These compounds were extracted into 5% trifluoroacetic acid (TFA) in methanol, derivatized with 4-(4,5-diphenyl-1H-imidazol-2-yl)-benzoyl chloride and separated either on a 250 x 1.5 mm i.d. octadecyl-silane (ODS) or a 150 x 2 mm i.d. OD-RH column. Linear calibration curves extending over a wide range of concentration that covers the practical samples were obtained for amphetamine, methamphetamine and their enantiomers (r = 0.999). Resolution values for amphetamine and methamphetamine enantiomers were 3.4 and 1.1, respectively. Intra- and inter-day variations of both the methods were not larger than 8.9% expressed as relative standard deviations (n >/= 5). The limits of detection at a signal-to-noise ratio of 3 obtained by both the methods were in the range of 1.0-4.7 fmol/5 microL injection with the achiral method being more sensitive. Abusers' hair samples were analyzed by the two methods and only the S(+)-enantiomers were found in eight Japanese abusers' hair samples. The achiral method was used to study the concentrations of these compounds in single black and white hair strands of abusers.